Oil control piston ring with expander bracelet - bracelet is toroidal and bears in arcuate groove in ring

摘要

A toroidal expander bracelet is made by winding steel into a coil and then forming a circle the two ends of the coil being interconnected by a piece of wire inserted in each end of the coil. The bracelet sits in an annular groove formed in a piston and urges a piston oil control ring against a cylinder wall. An arcuate groove is formed in the inner wall of the ring to accommodate the bracelet which is relieved along parts of its outer circumference to enable the ring tension to be correctly adjusted. The ring and bracelet may be chromium plated.